"We're focusing on the University of Pennsylvania because it's the biggest university in the area when it comes to animal abuse," said director Marianne, who declined to give her last name.

"In addition, it has the most violations of the Animal Welfare Act of any Ivy League institute."

The Physicians Committee for Responsible Medicine last year released a report stating all Ivy League schools had a “disturbingly high” number of violations and ranking Penn the worst offender.

Protesters especially took issue with the school's continued experimentation on primates.

"It's very hard to justify it because they're so close to us," Marianne said.

"They've done so many experiments and they've found nothing. They cured AIDS in chimps, but when tried to translate that to humans, it didn't work."

But Penn media relations director Ron Ozio said in an email the school's biomedical research "is aimed at finding treatments and cures for some of the most vexing diseases of our time, for both humans and animals" and "committed to maintaining the highest standard of care" for lab animals.

"The University carefully investigates any report of a potential animal welfare violation and takes corrective steps where necessary," he said.

Marianne contended the school has in the past bolted primates in cages to monitor their brain waves in times of food or sleep deprivation and is currently castrating baby pigs without anesthesia, supposedly a common industry practice undertaken to better understand the needs of farmers.

"I think if you dreamed up something you think is impossible, there's probably somebody somewhere doing it," she said.

Participant Carla Mariani said she was "shocked" to hear Penn practiced the alleged cruelties.

"Action would be the best outcome," she said of the rally. "But we definitely want to heighten awareness."